Gender Swap

It's the Golden Trio's 4th year at Hogwarts when something(other then the tri-wizard cup) happens. Something strange, very strange. Everyone's gender is changed, so the boys are girls and the girls are boys. Harry, Ron, and Hermione(Harriet, Rhoda,and Hermon) seem to be the only ones who can remember themselves as their original gender. Everyone's name, title, and appearance looks/seems similar, but as they would as the opposite gender. Can they get everyone back as they originally were, before it's to late?